var aneObj = function () {
  this.x = [];
  this.len = [];
}

aneObj.prototype.num = 50;
aneObj.prototype.init = function () {
  for (let i = 0; i < this.num; i++) {
    this.x[i] = i * 16 + Math.random() * 20;
    this.len[i] = 200 + Math.random() * 50;
  }
}
aneObj.prototype.draw = function () {
  ctx2.save();
  ctx2.globalAlpha = 0.6;
  ctx2.lineWidth = 20;
  ctx2.lineCap = 'round';
  ctx2.strokeStyle = '#3b154e';
  for (let i = 0; i < this.num; i++) {
    ctx2.beginPath();
    ctx2.moveTo(this.x[i], canHeight);
    ctx2.lineTo(this.x[i], canHeight - this.len[i]);
    ctx2.stroke();
  }
  ctx2.restore;
}